Appeal 3292617

The appeal is allowed, and planning permission is granted for the construction of a rear dormer window and raising the ridge height at [site address] , Herts [postcode] subject to the following conditions:

The development hereby permitted shall begin not later than three years from the date of this permission.

The materials to be used in the construction of the external surfaces of the development hereby permitted shall match those used in the existing building.

The development hereby permitted shall be carried out in accordance with the following plans: 19044/OS, 190440/01-1, 190440/01-2, 190440/01-3A, 190440/01-4, 19044/01-5, 190440/02- 1, 190440/02-2, 190440/02-3C, 190440/02-4, 190440/02-5, 190440/02-6A.

The appellant’s agent has drawn my attention to a previous planning permission at the appeal site to raise the height of the main house roof ridge and chimney by 510mm under local planning authority reference number 19/00388/FPH.

The appellant has supplied a corrected version of [name].19044/02-03 ([name]) which removes the remnants of a single storey side extension was being considered by the appellant. This version was not submitted as part of the original application; however, I do not consider any of the parties would be prejudiced by this approach and have proceeded to determine this appeal accordingly.

The description of development on the decision notice varies from that which was on the application form. For the purposes of precision, I have used the description on the decision notice.

The main issue is the effect of the proposed development on the character and appearance of the area.

Knights Templars Green is a modern residential cul de sac, set within a larger modern housing estate with a pleasant suburban feel. The area is dominated by detached two storey, brick-built houses with front and rear gardens, driveways, and garages. The appeal site (No 40) is situated on the bend in the road, set back behind a front garden and driveway which also serves a detached garage.

At the site visit, I took time to drive around the neighbouring streets and noticed that rear box dormers had been added to at least two properties in the area. However, these appeared to be smaller than that of the appeal proposals.

The appeal proposals would result in the addition of a substantial box dormer to the rear of the dwelling, which would run across the entire width of the house, incorporating the (already permitted) increased ridge height. The dimensions given for the proposals would be approximately 8.5m wide, 3m in depth and 2.5m in height. This would result in a volume of around 32.3sqm.

The officer’s report sets out that as a result in the increase in the ridge height of the property, the dormer would exceed the height of the ‘original’ dwelling.

The Town and Country Planning (General Permitted Development) (England) Order 2015 (the Order) as amended, and specifically Part 1 of Schedule 2 to the Order sets out what enlargements, improvements, alterations, and other additions a householder may make to their house and the area around it without the need for an application for planning permission (permitted development).

The appellant makes the case that a box dormer of similar dimensions as those proposed could be implemented under permitted development, had the permission for the increase in ridge height (under ref 19/00388/FPH) been implemented. The Order allows for such dormers to be added to ‘existing’ dwellings and does not stipulate that it must be to the ‘original’ dwelling (both of which are defined in the Permitted development rights for householders: Technical Guidance, MHCLG, September 2019).

The appellant therefore claims this as a ‘fallback’ position, which would be pursued if this appeal was dismissed. From their submissions, I consider there is a reasonable chance that as an alternative, the appellants would implement the fallback position in the event this appeal were to be dismissed. In light of this, I have considered the design of the box dormer ‘permitted development’ scheme, I agree with the appellant that the ‘fallback’ position in this case would be marginally more harmful to the character and appearance of the area than that of the appeal proposal.

I have assessed the application against the relevant parts of the [name] (2009), which informs policy GD1 ([name]) of the Stevenage Local Plan (2019) (LP). Policy GD1 of the LP seeks to promote good design in all forms of development and within the SPD it states that a dormer should not extend over more than half of the roof slope; and a minimum 500mm wide area of original roof should be retained at the bottom and both sides of the dormer.

[name] agree that the dormer proposals are not in accordance with these criteria, it is clear to me that the appellant would likely implement a permitted development scheme which would not meet these criteria either. Indeed, permitted development would not be assessed against these policies in any case. Moreover, the design of the permitted development scheme, as I have already discussed, would be marginally more harmful to character and appearance.

To that end, having regard to the fallback position, I do not consider there would be harm to the character and appearance of the area resulting from the proposals, despite there being some conflict with the relevant parts of the SPD.

I have applied condition 1 and 3 in the interests of precision and certainty and condition 2 to protect the character and appearance of the area.

For the reasons given and having regard to all other matters raised, the appeal is allowed, subject to the conditions listed.